An endorsement is a notation on your driving licence that says you are legally permitted to operate a specific type of vehicle or cargo

An endorsement is not a separate licence — it is a code printed on your existing commercial driver's licence (CDL) that authorizes you to drive certain vehicle classes or haul certain materials. Without the correct endorsement, you cannot legally operate that vehicle or transport that cargo, even if you hold a CDL. For example, a Class A CDL without a tanker endorsement means you can drive a tractor-trailer, but you cannot haul liquids in a tank vehicle. The endorsement appears as a letter code on the front or back of your physical licence card.

Each state prints endorsements the same way — as single letters — but the specific endorsements available and their requirements vary slightly by state. The federal government sets the baseline requirements through the Commercial Driver's License Information System (CDLIS), but your state's DMV administers the test and issues the endorsement. You must pass a written test specific to that endorsement before the DMV will add it to your licence.

Key Takeaways

  • An endorsement is a code on your CDL that permits you to drive a specific vehicle type or transport specific cargo — you cannot legally do either without it.
  • The most common endorsements are H (hazardous materials), T (double/triple trailers), and N (tank vehicles), each requiring a separate written test.
  • You must pass the endorsement test at your state DMV before the code is added to your licence; you cannot drive under that endorsement until it appears on your card.
  • Endorsement requirements and test content are set by federal regulation, so the general structure is the same across states, but fees and processing timelines vary.
  • Some endorsements require a medical certificate or background check in addition to the written test.

The most common endorsements and what they allow you to do

H (Hazardous Materials) allows you to transport materials classified as hazardous by the U.S. Department of Transportation — explosives, flammable liquids, gases, poisons, radioactive materials, and corrosives. You must pass a written test covering hazmat regulations, placarding, shipping papers, and emergency procedures. You also need a Transportation Security Administration (TSA) background check before the DMV will issue this endorsement. The background check is separate from the written test and can take several weeks.

T (Double and Triple Trailers) allows you to tow two or three trailers at once. The test covers coupling and uncoupling procedures, weight distribution, braking systems for multiple trailers, and safe operation at highway speeds. This endorsement is required in most states if you want to pull doubles or triples; without it, you are limited to a single trailer even if your vehicle is capable of towing multiple units.

N (Tank Vehicles) allows you to haul liquids or gases in a tank vehicle — milk tankers, fuel tankers, chemical tankers. The test covers tank-specific handling, weight distribution in partially filled tanks, emergency procedures, and the physics of liquid surge. Tank vehicles handle differently than dry vans because the cargo shifts during acceleration and braking.

P (Passenger) allows you to operate a bus or other vehicle designed to carry 16 or more passengers. The test covers passenger safety procedures, emergency evacuation, wheelchair securement, and passenger management. This endorsement is required for school bus drivers, transit bus operators, and charter bus drivers.

S (School Bus) allows you to operate a school bus specifically. You must hold a P endorsement first, then pass an additional test covering school bus operations, child safety, loading and unloading procedures, and state-specific school transportation laws. Some states require a background check and fingerprinting for this endorsement.

X (Hazmat and Tank) is a combination endorsement that covers both hazardous materials and tank vehicles. You do not take a separate X test; instead, you pass both the H and T tests, and the DMV issues an X. This is common for drivers who haul hazardous liquids.

How to get an endorsement added to your licence

The process begins at your state DMV. You must visit in person to schedule the endorsement test; you cannot take it online or by mail. Bring your current CDL, proof of residency, and any documents required for that specific endorsement — for hazmat, this includes proof of TSA clearance or authorization to explore for it.

Study materials are available from your state DMV website, usually as a free PDF or online study guide. The Commercial Driver's License Manual published by the American Association of Motor Vehicle Administrators (AAMVA) is the standard reference across all states and covers all endorsement topics. Many states also offer practice tests online.

On test day, you will take a written exam at your DMV office. The test is typically 20 to 50 questions depending on the endorsement, and you usually need to score 80 percent or higher to pass. Some endorsements, like hazmat, require you to pass on your first attempt — if you fail, you may have to wait a set number of days (often 7 to 14 days) before retesting. Other endorsements allow when ready retesting.

If you pass, the DMV will issue you a new CDL card with the endorsement code printed on it. This usually takes 7 to 14 business days by mail, though some states offer same-day or next-day issuance at the office. You cannot legally operate under that endorsement until the code appears on your physical card — a receipt or temporary permit is not sufficient.

Endorsement fees and what they cover

Endorsement fees vary by state and endorsement type. Most states charge between $10 and $50 per endorsement test. Some states bundle multiple endorsements into one fee if you take them on the same day; others charge separately for each one. A few states charge more for hazmat or school bus endorsements because of the additional background check or processing involved.

The fee covers the written test and the licence reissuance. It does not cover any background checks, medical certificates, or training courses that may be required separately. For example, the hazmat endorsement fee covers the test, but the TSA background check is a separate federal process with its own timeline and, in some cases, its own fee.

Check your state DMV website for the exact fee schedule. Many states post endorsement fees online; if yours does not, call the CDL section of your DMV directly. Some states offer fee waivers or discounts for certain groups, though these are rare.

Requirements that go beyond the written test

Hazmat (H) endorsement: You must obtain TSA clearance before taking the test. This involves submitting fingerprints and undergoing a background check. The process can take 4 to 8 weeks. You cannot take the hazmat test until TSA clearance is complete. Some states allow you to explore for TSA clearance through the DMV; others require you to explore directly to TSA through a third-party vendor.

School Bus (S) endorsement: Most states require a background check, fingerprinting, and sometimes a medical examination. Some states also require a pre-test training course or ride-along observation. Requirements vary significantly by state, so check your state's specific rules before scheduling the test.

Passenger (P) endorsement: A few states require a medical certificate or vision test in addition to the written exam. Most do not, but verify with your DMV before testing.

If your state requires a medical certificate for any endorsement, you will need to visit a certified medical examiner and obtain a Medical Examination Report (MER). This is the same form used for CDL medical certification. The certificate is valid for 24 months.

What happens if you drive without the correct endorsement

Driving a vehicle or hauling cargo that requires an endorsement you do not have is a violation of federal motor carrier safety regulations. The penalty is a citation, a fine (typically $100 to $500 depending on the state and the specific violation), and a mark on your driving record. If you are caught operating a hazmat vehicle without an H endorsement, the fine is usually higher and can result in out-of-service orders from the Department of Transportation.

A violation can also affect your employment. Many trucking companies conduct regular audits of driver records, and an endorsement violation can result in suspension or termination. Insurance companies may also increase your premiums or deny coverage if you are cited for operating outside your endorsement authority.

If you are unsure whether your current endorsements cover the work you are doing, ask your dispatcher or safety manager before you accept the load. It is better to clarify before you drive than to face a citation on the road.

Renewing or removing an endorsement

Endorsements renew automatically when you renew your CDL. You do not take the endorsement test again unless your state requires periodic recertification for a specific endorsement (some states require hazmat drivers to retake the hazmat test every few years, though this is not federal law). Check your state's renewal requirements when your CDL expiration date approaches.

If you want to remove an endorsement from your licence, you can request this at your DMV. There is usually no fee. You might do this if you no longer haul hazmat or operate a school bus and want to simplify your licence. Removing an endorsement does not affect your CDL itself — you keep your Class A, B, or C designation.

Frequently Asked Questions

Can I take multiple endorsement tests on the same day?

Yes. Most states allow you to take as many endorsement tests as you want in one visit, though you will need to study for each one separately. Some states charge one fee for multiple tests taken the same day; others charge per test. Call your DMV to confirm the fee structure before you schedule.

What if I fail the endorsement test?

You can retake it. Most states allow you to retake an endorsement test when ready or after a short waiting period (typically 7 to 14 days). You will pay the test fee again. There is no limit on the number of attempts, though some employers may have their own policies about retesting.

Do I need training before taking an endorsement test?

Federal law does not require formal training for most endorsements — the written test is the only requirement. However, some states require training for school bus endorsements, and some employers require training before allowing a driver to haul hazmat or operate doubles. Check your state's rules and your employer's policy.

Can I get an endorsement if I have a suspended or revoked licence?

No. Your CDL must be valid and in good standing to add an endorsement. If your licence is suspended or revoked, you must resolve that issue first before you can test for an endorsement.

How long does it take to get an endorsement after I pass the test?

The written test result is usually known when ready or within a few days. The physical CDL card with the endorsement printed on it typically arrives by mail within 7 to 14 business days. Some states offer same-day or next-day issuance at the DMV office for an additional fee. You cannot legally operate under the endorsement until the code appears on your physical card.